Impact of Sarcoidosis on In-hospital Outcomes Among Patients with Atrial Fibrillation: A Nationwide Readmissions Database Analysis

Sarcoidosis is a disease that involves multiple organs, including the cardiovascular system. While cardiac sarcoidosis has been increasingly recognized, the impact of sarcoidosis on atrial fibrillation (AF) is not well established. This study aimed to analyze the impact of sarcoidosis on in-hospital outcomes among patients who were admitted for a primary diagnosis of AF. Using the all-payer, nationally representative Nationwide Readmissions Database, our study included patients aged ≥18 years who were admitted for AF between 2017–2020. We stratified the cohort into two groups depending on the presence of sarcoidosis diagnosis. The in-hospital outcomes were assessed between the two groups via propensity score analysis. A total of 1031 (0.27%) AF patients with sarcoidosis and 387,380 (99.73%) AF patients without sarcoidosis were identified in our analysis. Our propensity score analysis of 1031 (50%) patients with AF and sarcoidosis and 1031 (50%) patients with AF but without sarcoidosis revealed comparable outcomes in early mortality (1.55% vs. 1.55%, P = 1.000), prolonged hospital stay (9.51% vs. 9.70%, P = .874), non-home discharge (7.95% vs. 9.89%, P = .108), and 30-day readmission (13.29% vs. 13.69%, P = .797) between the two groups. The cumulative cost of hospitalization was also similar in both groups ($12,632.25 vs. $12,532.63, P = .839). The in-hospital adverse event rates were comparable in both groups. Sarcoidosis is not a risk factor for poorer in-hospital outcomes following AF admission. These findings provide valuable insights into the effectiveness of the current guideline for AF management in patients with concomitant sarcoidosis and AF.


Background
3][4][5] Atrial fibrillation (AF) remains the most common type of supraventricular arrhythmia in patients with sarcoidosis, with a prevalence of 12%-18%. 6,7However, data on the impact of sarcoidosis on in-hospital outcomes among those with AF are not well established.

Methods
We queried the all-payer, nationally representative Nationwide Readmissions Database to analyze patients aged ≥18 years who were admitted for AF between January and November during each calendar year from 2017-2020.We stratified the cohort into two groups based on the presence or absence of sarcoidosis diagnosis using the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) diagnosis code D86.The main outcomes examined were: (1) in-hospital adverse events, (2) length of stay, (3) discharge disposition, (4) 30-day readmission rate, (5) early mortality (mortality during index hospitalization and readmission), and (6) cumulative cost of hospitalization.As the Nationwide Readmissions Database provides de-identified patient data and is publicly accessible, institutional review board approval was not required for this study.
Continuous data were summarized as mean with standard deviation values or median with interquartile range (Q1, Q3) values depending on their distribution; differences between groups were using Wilcoxon rank-sum tests.Categorical data were summarized as

Discussion
This study is the first to provide insights on in-hospital adverse events and 30-day readmission rates among patients with and without sarcoidosis who were admitted for AF in a real-world setting.Despite an increased risk of AF and greater comorbidity burden among patients with sarcoidosis, our study suggests that patients with sarcoidosis and AF did not experience poorer in-hospital outcomes when compared to patients without sarcoidosis. 6AF in sarcoidosis was hypothesized to be caused by atrium granuloma leading to scarring and by sarcoid involvement of the lungs and left ventricle, resulting in increased end-diastolic pressure. 6,8The non-inferior outcomes observed in sarcoidosis provide a reflection of contemporary realworld data on the effectiveness of AF management in sarcoidosis by early diagnosis and treatment of cardiac sarcoidosis as well as early intervention, including rate control, rhythm control, or even catheter ablation, as per guideline in all AF patients regardless of the underlying etiology. 5,9,10Our study also demonstrates that sarcoidosis is not an independent risk factor of in-hospital adverse events during hospitalization.

Limitations
It is important to acknowledge a few main limitations of this study.First, as with most large administrative database studies, the main limitation includes potential miscoding in primary diagnoses and under-reporting of secondary diagnoses.Next, the out-of-hospital deaths that occurred prior to readmission were not recorded, which limits our early mortality to in-hospital mortality.Furthermore, clinical information, including the duration of AF, cardiac involvement of sarcoidosis, and anti-arrhythmic medications, was not available in the database, limiting our attempts to explore the impact of these clinical variables on hospital outcomes.

Conclusion
Our study suggests that sarcoidosis is not associated with poorer hospital outcomes among patients hospitalized for AF.These findings provide valuable insights into the effectiveness of the current guideline for AF management in patients with concomitant sarcoidosis and AF.

Table 1 :
Baseline Characteristics of the Patient Cohort

AF Patients with Sarcoidosis AF Patients Without Sarcoidosis
Abbreviations: AF, atrial fibrillation; ICD, implantable cardioverter-defibrillator; PPM, permanent pacemaker; SD, standard deviation.Impact of Sarcoidosis on In-hospital Outcomes Among Patients with AFThe Journal of Innovations in Cardiac Rhythm Management, March 2024 counts and percentages; differences between groups were tested using Pearson's chi-squared test.All tests were twosided with P ≤ .05,indicatingstatisticalsignificance.Statistical analyses were conducted using Stata version 12.1 (Stata Corporation, College Station, TX, USA).To identify the association between sarcoidosis and in-hospital outcomes, weighted propensity score matching was first performed with a caliper of 0.2 with a nearest-neighbor ratio of 1:1 for each hospital outcome.Then, all variables outlined in Table1, including sarcoidosis, were included in the univariable analysis to study their association with the outcome variables listed in Table2.Those relevant variables with P < .1 were included in a multivariable model for conditional logistic regression analyses.

Table 2 :
In-hospital Outcomes of AF Patients with Sarcoidosis Versus Without Sarcoidosis via Propensity Score Analysis

Table 3 :
Analysis of Hospital Outcomes of AF Patients with Versus Without Sarcoidosis